K2view's TDM enables overriding Global variables on both environment and task levels:
Click to read more about overriding Fabric settings by a task's execution.
The Task variables tab in the task's Advanced settings displays the list of variables set on a task level and enables setting variables on a task.
Click Add variable to set a variable value on the task. The following pop-up window opens:

The task creator can check the Add parameters at execution checkbox to allow the task runner to add new variable overrides at execution time, in addition to any variables already defined in the task. If this checkbox is unchecked, the task runner cannot add new variables at execution.
Each variable row has a lock icon. The task creator can unlock individual variables to allow the task runner to edit their values at execution time:
At execution time, all variables are displayed, but the task runner can only edit the values of unlocked variables.
K2view's TDM enables overriding Global variables on both environment and task levels:
Click to read more about overriding Fabric settings by a task's execution.
The Task variables tab in the task's Advanced settings displays the list of variables set on a task level and enables setting variables on a task.
Click Add variable to set a variable value on the task. The following pop-up window opens:

The task creator can check the Add parameters at execution checkbox to allow the task runner to add new variable overrides at execution time, in addition to any variables already defined in the task. If this checkbox is unchecked, the task runner cannot add new variables at execution.
Each variable row has a lock icon. The task creator can unlock individual variables to allow the task runner to edit their values at execution time:
At execution time, all variables are displayed, but the task runner can only edit the values of unlocked variables.